Add Utils.wait()

src/core/session.ts

         this._active = false; // set before wait()
 
         // wait a few ms, so that the GPU is no longer sending any data
-        const wait = (ms: number) => new Speedy.Promise<void>(resolve => {
-            setTimeout(resolve, ms);
-        });
-
-        // release resources
-        return wait(100).then(() => Speedy.Promise.all(
+        // then, release resources
+        return Utils.wait(100).then(() => Speedy.Promise.all(
 
             // release trackers
             this._trackers.map(tracker => tracker._release())

src/utils/utils.ts

 
 import Speedy from 'speedy-vision';
 import { SpeedySize } from 'speedy-vision/types/core/speedy-size';
+import { SpeedyPromise } from 'speedy-vision/types/core/speedy-promise';
 import { AssertionError, IllegalArgumentError } from './errors';
 import { Resolution, computeResolution } from './resolution';
 
     }
 
     /**
+     * Wait a few milliseconds
+     * @param milliseconds how long should we wait?
+     * @returns a promise that resolves soon after the specified time
+     */
+    static wait(milliseconds: number): SpeedyPromise<void>
+    {
+        return new Speedy.Promise<void>(resolve => {
+            setTimeout(resolve, milliseconds);
+        });
+    }
+
+    /**
      * Convert a resolution type to a resolution measured in pixels
      * @param resolution resolution type
      * @param aspectRatio width / height ratio